This invention relates to mechanisms for towing vehicles and, more particularly, to a wheel lift towing apparatus for engaging the front or rear wheels of a vehicle to be towed and for lifting the vehicle.
A wide variety of towing mechanisms are available for use on the rear end of a tow truck or other towing vehicle and which are adapted to lift one end of an immobilized vehicle for towing purposes. Such mechanisms range from elaborate overhead boom structures, normally employing slings for engaging an end of the vehicle to be towed, to rather crude jack type apparatus mounted in the rear bumper area of the towing vehicle. The most widely used mechanisms presently available include some form of wheel lift apparatus for engaging either the front or rear wheels of an immobilized vehicle to lift the vehicle during towing. The wheel lift apparatus may be suspended from an overhead boom or crane type winch or, as has become increasingly popular, the wheel lift apparatus is mounted at the rear end of the tow truck.
Conventionally, the rear mounted wheel lift apparatus include means for mounting a lower boom to the rear end of the tow truck, the boom extending toward the underside of the immobilized vehicle. A pair of cradle-type carriages are mounted on the free end of the lower boom in transversely spaced relationship for engaging the underside of the wheels. The boom and carriages are raised and lowered to raise and lower the immobilized vehicle. Raising of the boom and carriages can be accomplished by such means as hydraulic piston and cylinder devices or by a winch cable lowered from the overhead boom. The lower boom and carriage assembly is mounted at the rear bumper area of the tow truck by various types of means for affording raising and lowering of the assembly. For instance, the lower boom simply may be pivotally mounted to the rear of the tow truck or to the underside of the truck. The boom may have a vertical post telescoped within a hollow verticle post fixed to the rear end of the tow truck. Most such mounting means for the lower boom either are quite cumbersome or create a problem in affording only a limited range of lifting movement for the immobilized vehicle.
Another problem with conventional wheel lift apparatus is that the carriages at the end of the lower boom, for engaging the underside of the wheels of the immobilized vehicle, are difficult to position beneath the wheels in cramped surroundings such as near a roadway curb. For instance, most such wheel carriages have a forward fixed frame portion for engaging the front of the wheels. The carriage is in the form of a rearwardly extending fork, and a removable rod is inserted between the arms of the fork for engaging the rear of the wheels. Should the vehicle be immobilized near a roadway curb, it either is impossible to insert the support rod or an operator must crawl completely under the immobilized vehicle to insert the rod from the inside of the carriage fork.
Another problem prevalent with wheel lift apparatus presently available is the inability to compactly fold the apparatus when not in use, particularly for folding the apparatus out of the way of operation of an overhead boom and sling mechanism.
This invention is directed to a novel wheel lift towing apparatus having features which solve one or more of the above-identified problems.